Dry-pipe valve



Sept. 28 1926. 1,601,515

E. TYDEN my PIPE VALVE Filgd August 25, 1923 g lllllllllllllllllllllllllllml I film If l Patented Sept. 28, 1926.

UNITED STATES EMIL TYDEN, OF EVANSTON, ILLINOIS.

DRY-PIPE VALVEI Application filed August 25, 1923. Serial No. 659,335.

The purpose of this invention is to provide an improved and simplified construction for accelerating the action of'thedry pipe valve of the dry pipe fire extinguisher system adapted to produce such acceleration upon the opening of the dry pipe valve upon the occurrence of negligible air leakage,- less than would result from opening a single sprinkler head. It consists inv the elements and features of construction shown and described as indicated in the claims.

In the drawings:

Figure 1 is a partly sectional front elevation of a dry pipe valve, and its connected air and water pipes equipped with the device embodying this invention, and section being made through the dry pipe valve casing at the connection with the interseat chamber of a pipe for admitting pressure thereto from one of the pressure regions of the system.

Figure 2 is a section at the line 2-2 in Figure 1.

Figure 3 is an elevation looking in the direction of the arrow 3 in Figure 1.

Figure 4 is a detail section on an enlarged scale, axial with respect to the air passages of the casing and connection of the sylphon shown in Figure 2.

In the structure shown in the drawings, (A) is, the dry pipe valve casing or body, hereinafter referred to as the valve body, (B) is the water inlet pipe, (C) the pipe leading to the sprinkler system, which in the normal condition of the apparatus when. set for its purpose is occupied'by air under pressure. (D) is the dry pipe main valve having the usual construction for seating at two concentric seats (A and A )'between which there is the usual interseat chamber (a) in which the pressure is normally atmospheric, so that the super-atmospheric pressure operating both the valve D defined by the outer seat (A as compared with the area defined by the interseat (A )"over which the water pressure is operative at the underside of the valve, insures the valve (D) being held seated by super-atmospheric pressure in the system, which is usually maintained at about thirty pounds, as against the water pressure inv the main which may reach one hundred pounds.

When a sprinkler head is opened, causing reduction of the super-atmospheric pressure in thesystem, which eventually results in Y the dry pipemain valve (D) being opened by water pressure, and the water being sent to the open sprinkler head, it is desirable that the opening of the valve (D) should be delayed as little as possible after the sprinkler head is opened and thereduction of air pressure in the system begins; but when only a single sprinkler head is opened by the fire, it may require a very appreciable length of time for the air pressure to be reduced so as to permit the main dry pipe valve (D) to open.- The purpose of the present invention is to cause the amount of reduction of air pressure in the system which will be experienced almost instantly upon the opening of asingle sprinkler head, to result in overcoming the excess pressure at the upper side of the valve which holds it seated, so

that the valve will open almost instantly upon the opening of a sprinkler head. This is effected by means of devices which are sensitive to the slight reduction of the pressure which occurs almost instantly upon the opening of the sprinkler head, and before that reduction has become considerable, and which, responding to that slight reduction operate to open a communication from one of the pressure regions,either the region of water pressure operating under the valve over the lesser area of the inner seat,-or the region of air pressure operating over the greater area above the valve defined by the outer seat, to said interseat chamber, being hereafter referred to as the atmospheric pressure chamber in which, normally, when the device is set up for its purpose, the pressure is substantially atmospheric.

These devices are designed with a view to responding as indicated to the reduction of pressure which follows the .openingof a single sprinkler head, while not responding to less reduction of pressure which may result from minor negligible leakages in the system. These devices will now be described.

Into the wall of the interseat or atmospheric pressure chamber of the dry pipe valve body, A, there is screwed through a suitably threaded aperture provided therein, a valve fitting, M, having a valve, M seating inwardly at the seat around the discharge port m of said fitting, and provided with a spring, m, tending to seat it. This valve has its stem fluted, as seen at m for forming longitudinal ribs, m ,by which it is guided in the guide bearing provided for it at M and for admittingthe pressure around said stem into the guide bearing socket so that the movement of the valve will not tend to produce a partial vacuum or pressure interfering with its movement, the fitting has a lateral branch, M leading into the chamber, in the valve fitting, M, said lateral branch being interiorlyythreaded for connection thereto of a pipe T nipple, N, whose cross member is connected by a pipe, N to the air pipe, G, and by the pipe, N, to the inlet neck of the main valve body to which the water pipe, B is attached. Said pipes, -N* and N, are provided, respectively, with check valves, N and N opening for flow toward the fitting, M. Fulcrumed within thecha'mber, a, there is a lever, P, one arm of which extends for encounter with the inner end of the alvc, M exposed within the chamber, a, through its port, m The opposite arm of the lever is weighted, as seen at P so that it tends by gravity to ooen the valve, M and hold it open. Pivot'ed within the chamber, a, is a latch, O, adapted by its upper end to engage a ratchet notch, 37 in the end of the lever, P, and provided with a spring tending to hold it so engaged, said notch being conveniently made in the weight, P which terminates said lever. The position or the latch, O', is such as to engage its nose with the notch, in the end "of the lever when the lever is lifted, so far as to permit the valve, M to be seated. Said latch, ,O, has an operating connection extending through the wall of the chamber, a. This connection is afforded as hereinafter -d escribed.

Upon the dry pipe valve body there is mounted a casing, G, in which there is carried by attachment at the center 01 oiie end to the head plate, G, of said casing, an'elas ti'cally expansible and contractible hollow device, H, of the character commonly known in the arts and industries employing such "devices, as a sylphon and so herein after referred to. The plate, G is provided with two connections with the air pipe, C, "of the sprinkler system, said connections being through branches, J and J 01 a pipe, J, leading from the pipe, C. The branch, J leads into the sylphon, H, and the branch, 3, leads to the chamber of the casing, G,'outside the sylphon. The ports of communication of the two pipes, J and J with the casing chamber and with the sylphon respectively, are of different size, the port, 7' leadin into the sylphon being much smaller than the port, j which leads into the chamber oi": said casing, G, outside the sylphon. The sylphon casing, G, is mounted by its open end on the dry pipe valve body, A,the sylphon, H, being mounted in said casing upon the opposite end or head of the casing, said open end encompassin'g an aperture, a in the wall 01 the chamber, a, of the dry pipe valve body and the sylphon has a stem, K, which extends through said aperture, terminating within the chamber, a, in position to encounter the lower end of the latch, O, and disengage its upper end from the weight, 10 upon the inthrust oi the sylphon stem. It will be understood that the casing, G, is mounted air-tight at its junction with the dry pipe valve body.

It will be observed that when the system is under the usual air pressure in the pipe, C, that pressure is communicated both to the cavity of the sylphon, H, and to the cavity of the casing, G, around the sylphon, the full pressure in the pipe, C, being eventually experienced in both said cavities, though it obtains much slower access to the casing cavity than to the sylphon cavity. 'But ina few minutes after introducing the customary air pressure to the system, both said cavities are under equal pressure, and the sylphon will be in its normal position as to collapse and expansion, that is to say susceptible of being collapsed or expanded according to the relation of the pressure inside and outside of it. Under these conditions it will be understood that upon reduction of pressure in the air pressure region of the system (the pipe, C), such reduction will be experienced almost instantly in the chamber, G, outside the sylphon, but very slowly within the sylphon cavity, with the result that immediately upon the occurrence of such reduction of pressure, it the reduction is suliici'ent to affect the sylphon in view 0t its stifin'ess, the sylphon will expand because the pressure inside of it will be greater than the pressure outside of it, and the stem, K, will be thrust in through the aperture in the wall of the chamber, a, and disengage the latch, 0, from the weighted lever, P, allowingthe lever to fall and release the valve, M permitting it to open and-admit pressure from either the 'air pressure or the water pressure region according to which pressure is at the moment the greater, the greater pressure operating to close the valve, ll or Nflin the pipe conne'cted with the lower pressure.

Since the atmospheric pressure chamber, a, is n'ecesi-tarily provided with a drainage port which must be closed in order to develop s'uper-atmospheric pressure in said chamber upon the opening of the valve, M the lever, P, carries a valve, T, for closing the drainage port, a by the dropping of the lever upon its release from the latch. To prevent leakage around the stem, K, when the pressure has been admitted to the chamber, a, by the -inthrust of the stem disengaging the latch and releasing the lever for opening the valve, M the outer port of the aperture, a through which the stem, K, protrudes intothe chamber, a, is finished as a valve seat a and the stem, K, has an enlargement, K operating as a valve seating at said seat at the inthrust position of the lever. Since the pressure inside and outside the sylphon will become equalized very shortly after the reduction of air pressure in the system which at the start causes difference in the pressure inside and outside the sylphon, the sylphon stem will be retracted shortly after the pressure has been admitted to the chamber, a, and in order that at this stage leakage around the stem, K, may be prevented, there is mounted on said stem at the inner side a valve member, K which seats at the inner port of the aperture, (F. The leakage which may occur during the retracting movement of the stem while the sylphon pressures are becoming equalized, will be negligible both because the leakage will be small and because the time will be short. in latched position, the drainage valve, T, has its stem, T extending down through the drainage port so as to be accessible below the same for pushing the drainage valve up against the underside of the weighted lever and lifting it to a position at which it is engaged by the latch, O.

The drainage port nipple, t, is shown delivering into a spout or hopper, V, bracketed onto the lower side of the valve body for receiving the drainage and conducting it by suitable pipe connection to a proper point for receiving the same. This hopper will be suspended at sufficient distance below the nipple to leave convenient access for the hand of the operator to reach the stem of the drainage valve for lifting the weighted lever as described.

I claim 1. In a dry pipe sprinkler system, in combination with a dry pipe main valve constructed for exposing differential areas to the water and air pressures respectively at its opposite sides, and having for that purpose, at the water inlet side a chamber in which the pressure is normally substantially atmospheric; a passage leading from the region of one of said pressures to said chamber, a valve controlling said passage having a part exposed in said chamber; a lever in said chamber positioned for engaging said exposed part for opening the valve; means by which the lever normally tends to open the valve and hold it open; a latching device in the chamber for restraining the For seating the weighted lever, P,

lever against said valve-opening action; means for engaging the lever with the latching device, said latching device having means operable exteriorly of the chamber to disengage it for releasing the lever to permit the latter to open the valve, and means operated by reduction of pressure in the air pressure region of the dry pipe system for operating said latch disengaging means.

2. In the construction defined in claim 1, foregoing, the valve-controlling lever being weighted for normally operating the valve for opening the same by gravity.

3. In the construction defined in claim 1, foregoing, the means for operating the latch disengaging means comprising a casing mounted on the outer side of the chamber encompassing the emergence from the atmospheric pressure chamber of the latch disengaging means; a sylphon device enclosed in said chamber having one end fixed thereto and the opposite end operatively connected with said latch disengaging means; duct connections leading from a pressure region of the system having ports of communication with said casing and with the cavity of the sylphon within the casing independently of the communication with the casing, one of said ports being restricted relatively tothe other.

4;. In the construction defined in claim 1, foregoing, the means for operating the valve which controls the pressure passage leading'into the atmospheric pressure chamber comprising a casing mounted on the outer side of the chamber encompassing the emergence from the atmospheric pressure chamber of the latch disengaging means; a sylphon device enclosed in said chamber having one end fixed thereto and the opposite end operatively connected withthe latch disengaging means; duct connections from a pressure region of the sprinkler system for admitting said pressure into the casing and into the cavity of the sylphon independently of the admission into the casing, the port of communication with the sylphon being restricted relatively to the port of communication with the casing.

In testimony whereof, I have hereunto set my hand at Chicago, Illinois, this 16th day of August, 1923.

EMIL TYDEN. 

